University of Bordeaux 1, UMR CNRS 5805 EPOC, Place du Docteur Peyneau, 33120 Arcachon, France.
CNRS, EPOC, UMR 5805, 33405 Talence, Cedex, France.
Environ Pollut. 2014 Sep;192:74-82. doi: 10.1016/j.envpol.2014.04.012. Epub 2014 Jun 2.
This study aimed to assess the recovery capacity of the freshwater bivalve Corbicula fluminea subjected to industrial metal discharges (Cd, Zn). After a 24-day exposure in a metal-contaminated river, bivalves were transferred and maintained in the laboratory for one year under metal-free conditions. Metal accumulation, metallothionein production and genetic expressions of genes involved in metal stress were studied. Results demonstrated the high persistence of Cd in tissues (only 73% eliminated after 365 days) whereas Zn was rapidly depurated. The Cd half-life was estimated around 240 days. Metallothioneins were strongly induced within the 28 first days of decontamination, then decreased by 45% after 365 days. The metal exposure of bivalves led to a significant gene induction. After 28 days, most of the genes were no longer overexpressed, suggesting that the bivalves may withstand small amounts of non-essential metals in their tissues without showing signs of detrimental effects on the tested genes.
本研究旨在评估淡水双壳类生物河蚬（Corbicula fluminea）对工业金属排放（Cd、Zn）的恢复能力。在受金属污染的河流中暴露 24 天后，将双壳类动物转移并在无金属条件下实验室中维持一年。研究了金属积累、金属硫蛋白的产生以及与金属应激相关基因的遗传表达。结果表明，Cd 在组织中的持久性很高（365 天后仅消除了 73%），而 Zn 则被迅速排出。Cd 的半衰期约为 240 天。金属硫蛋白在脱污染的前 28 天内被强烈诱导，然后在 365 天后减少 45%。双壳类动物暴露于金属中会导致基因显著诱导。28 天后，大多数基因不再过度表达，这表明双壳类动物可以在组织中耐受少量非必需金属，而不会对测试基因产生有害影响。
